PHILADELPHIA — DeSean Jackson, like everyone else in Eagles Nation, still isn’t sure who is going to be throwing him the football when it counts, against the Washington Redskins on Sept. 9.

To Jackson, who figures to have a very productive year in Chip Kelly’s new offense, all three potential quarterbacks — Mike Vick, Matt Barkley and Nick Foles — have looked good in the spring practices.

“All of them are getting the job done,” Jackson said, as the Eagles opened their mandatory three-day minicamp Tuesday at the NovaCare Complex. “They’re all working hard, learning the offense like all of us, and I think all of them can play.”

Asked specifically about the veteran of the group, Vick, Jackson might have tipped his hand on who his favorite is.

“Mike is doing a great job,” Jackson said. “This offense just fits him, because he’s a two-way quarterback. But he’s been doing a good job of sitting in the pocket and taking the offense and letting it come to him. He’s doing everything they’re asking of him.”

While the calendar has just turned to June and that Redskins game is still over three months away, the Eagles are expecting a lot of Jackson, the mercurial receiver whose career has taken interesting turns in his five years with the team.

The latest turn was his firing of agent Drew Rosenhaus and his potential hiring of Jay-Z’s group. Tuesday, he tried to stay away from agent talk.

“I’m not sure what I’m going to do yet,” he said. “It’s wide open right now. I’m not even really thinking about it. I’m all about football.”

Last year, despite a new long-term contract, he had career lows in games played (11), catches (45), yards (700) and touchdowns (2). After consecutive 1,000-plus yard seasons in 2009 and 2010, he’s been kept under 1,000 the past two years.

This year that’s expected to change, in a lot of ways.

“I’m getting more and more used to this offense — I think we all are,” Jackson said. “I mean, when we first started it was tricky. It was like night and day from what we were used to doing. Now, I think we’re all getting the hang of it.”

Jackson, who for the first time in his professional career has been at every offseason workout, voluntary or not, has learned every possible position he may play in Kelly’s system. That means he might line up everywhere from in the slot, to out wide — left or right — to even running back.

“That was the hardest part,” Jackson said. “When I got here out of college, I was a Z receiver, that’s all I had to learn. Now, I’m learning everything.”

Again, Kelly’s whole idea is to create mismatches and get the best use of his players. It’s kind of like Andy Reid’s version of putting his players in the right position to make plays.

Only Kelly doesn’t say that over and over, at least not yet.

Jackson, so far, likes the idea.

“I definitely do like that idea,” he said of being versatile. “When we come to the line of scrimmage, the defense doesn’t know where we’re going to be. NFL teams scout you very well and watch a lot of film, and things like that. This year that’s going to be very hard to do.”

NOTES: The team had 87 of the 90 players on the roster present at Tuesday’s first mandatory day of minicamp. Missing were free agent defensive tackle Issac Sopoaga, who was excused to attend a funeral, and rookie draft picks, tight end Zach Ertz and cornerback Brandon Poyer, whose colleges have not graduated yet. Offensive linemen Jason Kelce and Evan Mathis were back in action for the first time since going on injured reserve last season. Kelce, who suffered a torn MCL and partially torn ACL last season, said he felt fine except for some mild tendinitis in his knee. Mathis, who was out with an ankle injury, also said he was fine.